High frequency of bladder cancer in polish population and relatively low sensitivity of cancer detection in early stages is a main reason for search for other, more sensitive diagnostic tests. Photodynamic diagnosis based on accumulation of photosensitizers, porphirin derived compounds emitting fluorescence in laser light is a promising tool for detecting of small or poorly differentiated neoplastic changes. On the other hand we can use photodynamic therapy when in laser light photosensitizers generate free oxygen radicals and destroy neoplastic tissue. Photodynamic therapy is a perfect tool in bladder cancer treatment especially in case of early stage or multicentric neoplastic changes that are difficult to resect in traditional endoscopic way.